Sand mulling apparatus for foundries



Quit. 10, 1933.

G. F URMAN SAND HULLING APPAfiATHS FOR FOUNDBIES 3 Sheets-Sheet 1 Filed Feb. 15, 1930 Oc t. 10', 1933. G. FURMAN SAND MULLING APPARATUS FOR FOUNDRIES Filed Feb. 15, 19"0 3 Sheets-Sheet 2 Mwv O t O lylllllllll Oct. 10, 1933. G. FU'RMAN SAND MULLING APPARATUS FOR FOUNDRIES Filed Feb, 15, 1930 3 Sheets-Sheet Patented Oct. 10,1933 1 SAND MULLING APPARATUS FOR FOUNDBIES George Furman, Chicago, 1 assignor to The Beardsley & Piper Company, Chicago, Ill., corporation of Illinois 7 Application February 15,1930. Serial No. 428,587 7 4 Claims. (01. 83- 45) The present invention relates generally to apparatus for mulling molding sand. More particularly the invention relates to that type of sand mulling apparatus which is adapted for use in a foundry or similar establishment and comprises a frame-structure, a member on the structure for supporting the sand, and a mulling unit which embodies one or more loosely mounted wheels or mullers and operates, during drive thereof, to swing or rotate the wheels bodily in a circular path over the sand supporting member for mulling purposes.

One object of the invention is to provide a mulling. apparatus of the aforementioned type in which the member for supporting the sand is in the form of an endless belt which presents a smooth and even sand supporting surface and operates, during drive thereof, to feed the sand progressively into'the path of the mullers and then to discharge the mulled sand into a hopper or onto the receiving end of a second conveyor.

Another object of the invention is toprQ-' vide a sand mulling apparatus of the type under consideration in which the endless belt is formed of a resilient material such, for example, as rubber, and operates to suport the sand yield ingly and in such a manner that an eillcient mulling action is produced by the mullers with- 76'ut likelihood of the sand being pulverized or crushed to such an extent that its permeability is reduced to a point wherein it is unflt for use in connection with molds.

A further object of the invention is to 'provide a mulling apparatus in which thetread or peripheralpart of the mullers as. well as the endless belt is formed of rubber or a similar resilient material so that the sand is engaged frictionally as well as yieldingly and is mulled to the desired extent in a comparatively short period of time.

A still further object of the invention is to provide a sand mulling apparatus which is generally of new and improved construction and is an improvement upon previously designed apparatus for the-same purpose by virtue of the fact that it permits 0! a continuous operation and operates to mull the sand efliciently and in an expeditious ma er.

Additionally it is con plated as one of the objects of the invention roviding a mulling unitwhich embodies improved means for supporting and swinging the mullers.

Other objects of the invention and the various advantages and characteristics of the present construction will be apparent from a consideration of the following detailed description. The invention consists in the several novel features hereinafter set forth and more particularly defined by the claimsat the conclusion hereof. x v

In the drawings which accompany and form a part of this specification or disclosure and in which like numerals of'reference denote corresponding parts throughout the several views: Figure 1 is aside elevational view of a mulling apparatus embodying the invention;

Figure 2 is a plan view; Figure 3 is a vertical longitudinal section taken on the line 3-4: of Figure 2 and disclos-' ing in detail the construction and arrangement of the endless belt for feeding the sand progressively to mullers; Q

Figure 4 is a vertical transverse section showing one of the mulling units and the drive mechanism therefor;

Figure 5 is a section taken on the of Figure 4:

Figure 6' is a horizontal section taken on so 1ine6-6ofFigure4;and 7 Figure 7 is a horizontal section taken on the line 7-7 of Figure 4.

The apparatus which forms the subject matter of the invention is adapted primarily for use in a foundary and serves to'muli, mix or recondition molding sand. It comprises an endless belt 8 which receives the sand that is to be mulled or mixed from a reservoir 9 and operates. during drive thereof, to carry the sand the horizontally and in a rectilinear path past a pair 9" of mulling' units 10. r

The endless belt 8 is mounted in an elongated metallic supporting frame 11 which is supported by means of blocks 12 on the floor of the foundry. The frame embodies a pair of channel iron beams 13 which form the sides of the said frame and consist of vertically extending webs 14, out-. wardly extending upper flanges 15 andoutwardly extending lower flanges 16. The lower flanges restupon and are suitably secured to the blocks 12. The frame, in addition to the channel iron side-formingbeams 13, comprises cross members 17. Thelatter are formed of channel iron bars and have the ends thereof connectedto the upper flanges 15 of the beams 13 by means of angle iron brackets 18. These brackets are welded or otherwise secured to the top faces of the flanges 15 and the contiguous parts of the cross members 17. An elongated substantially imperforate plate 19 rests upon and is supported by the cross members 17. This plate extends from one end of the supporting frame to the other and serves to support the upper reach of the belt 8.

The endless belt 8 is disposed between the beams 13 of the supporting frame. The receiving end of the belt extends around and is supportedby a drum 20 which is mounted on a transversely extending shaft 21. The ends of this sh'aft extend through elongated slots in the receiving ends of the beams 13 and are mounted in bearing blocks 22 which are slidably mounted in guideways 23 so that the drum 20 may be shifted in order to keep taut the belt 8. The guideways 23 are secured to the outer faces of the webs of the channel iron beams 13 and are connected to the bearing blocks 22 by means of screws 24. By manipulating these screws the drum 20 may be shifted into the desired position. The discharge end of the endless belt 8 extends around and is supported by a drum 25 which is fixedly secured to a shaft 26. The ends of this shaft extend through the discharge ends of the beams 13 and are journalled in bearings 2'7 which are fixed to the outer faces of the webs 14. The lower reach of the belt is carried by a longitudinal series of rollers 28 which are located beneath the cross members 17 and the plate 19 and embody at the ends thereof pintles 29. These pintles extend through apertures in the webs 14 of the channel iron side-forming beams and are journalled in bearing brackets 30 which are positioned directly above the lower flanges 16.

The belt 8 is adapted to be continuously driven by means of an electric motor 31 so as to cause the sand to be carried from the reservoir 9 and fed progressively under the mulling units 10.

The motor 31 is located at the discharge end' of the belt and is connected to drive reducing gearing which is mounted in a housing 32. The reducing gearing comprises a drive shaft 33 which is journalled in one end of the housing 32 and is connected by a coupling 34 to one end of the shaft 26 for the M25. When current is supplied to the motor 31 the rotor of the motor operates to drive the reducing gearing in the housing 32. This gearing in turn eifects a low speed drive of the shaft 26 and causes a continuous motion to be imparted to the belt. During drive of the belt the sand which, as hereinafter described, is supplied in regulated quantity from the reservoir 9, is precluded from being displaced laterally with respect to the side margins of the upper reach of the belt by means of a pair of sheet metal trough-forming strips 35. The latter extendfrom one end of the supporting frame to the other and are secured to the side margins of the plate 19 by means of angle iron bars 36. These bars comprise vertically'extending legs 36 and horizontally extending legs 36*. The vertically extending legs are riveted to the lower parts of the strips 35. The horizontally extending legs 36 are welded or otherwise secured to the top face of the plate 19. The strips 35 extend upwardly from the plate 19 and have their upper portions bent outwardly, as indicated in Figure 4, for troughforming purposes. The angle iron bars 36 are preferably arranged so that the strips 35 are located in close proximity to the side edges of the belt. The sand after being carried by the belt 8 past the mulling units is. discharged onto a conveyor 37. The latter is arranged so that they receiving end thereof is located beneath the discharge end of the endless belt 8. A characteristic and an advantage of utilizing an endless belt in connection with the mulling apparatus and as the sand supporting medium is that the sand is subjected but once to the action of the mulling units 10 and therefore the likelihood of the sand being crushed or pulverized to too great an extent is eliminated. Another advantage is that the mulling operation may be carried out continuously in that the sand is fed progressively from the reservoir into the path of the mulling units and it is not necessary to stop the apparatus for sand loading and unloading purposes. Still another feature or advantage of utilizing an endless belt as the member for supporting the sand resides in the fact that a smooth and even surface is presented to the sand and as a result a thorough and uniform mulling action is obtained during operation of the apparatus.

The endless belt 8 is formed of rubber or a similar resilient material so that the sand is supported yieldingly. As a result of this arrangement excessive crushing of the sand is avoided and the mulling operation is expedited for the reason that the sand is held frictionally as well as yieldingly. The mulling units 10 are positioned above the belt 8 and operate during drive of the belt to mull the sand so that it is adapted for use in forming molds. One of the units is located slightly inwardly of the receiving end of the belt and serves, during operation of the apparatus, to efiect a preliminary mulling of the sand. The other unit is located between the discharge end of the belt 8 and the first mentioned mulling unit and serves to complete the mulling of the sand.

Each of the mplling units comprises a pair of wheels or muliers 38 which-are loosely mounted on the ends-of a horizontally extending axle 39. This axle is carried by a spider 40 which is driven as hereinafter described, so as to swing the axle bodily and cause the mullers to travel in a circular path in orderto effect the desired mulling of the sand on the belt 8. The upper central portion of the spider 40 is drivably conn cted by means of a key 41 to the lower end-of vertically extending driving sleeve 42. The latter is supported from above in a cast metal housing structure 43. This housing structure consists of a hollow cylindrically shaped member 44 and a pairof horizontally extending arms 45. The latter extend transversely with respect to the supporting frame for the belt 8 and are supported above the plate 19 by means of a pair of brackets 46. These brackets are preferably formed of angle iron and embody legs 47, the lower ends of which are provided with horizontally extending lugs 48. The latter fit against the side margins of the plate 19 and are held rigidly in place by bolts 49. The brackets 46, in addition to the legs 47, embody horizontally extending portions 50 which underlie the outer ends of the arms 45 and are secured to the latter by bolts 51. The housing structure 43 is formed in two sections. These sectionsare pro- .vlded with flanges 52 which extend outwardly The cylindrical wall 44. The top wall 44 forms a support for an electric motor and is provided with a bearing g6 in which is journalled the rotor shaft 55 of the motor. The interior of the cylindrical member 44 forms a compartment 57 in which is disposed planetary or epicyclic gearing for driving the spider 40. The gearing is driven by the motor 55 and comprises a pinion 58 which is keyed to the rotor shaft 55* of the mtor; a plurality of gears 59 which are driven by the pinion 58, mesh with an internal gear 60 on the inner periphery of the side wall 44" of the memher 44 and are connected to a vertically extending tubularelement 61 by means of studs 62; a pinion 63 which is keyed or otherwise secured to the central portion of the element 61; and a plurality of gears 64 which are driven by the pinion 63, mesh with an internal gear 65 on the inner periphery of the side wall 44 and are connected to a flanged portion 42 on the upper end of the driving sleeve 42 by means of studs 66. The tubular element 61 is loosely mounted in the sleeve 42 and is provided at its upper end with a radially extending flange 61 which rests upon the intermediate'wall 44 and has sockets for receiving the studs 62. The driving sleeve 42 extends through a bearing member 67 which is formed integrally'with the bottom wall 44 of the member 44 and supports the flanged portion 42 so that the sleeve is supported against downward displacement. The lower end of the driving sleeve is provided with a nut 68 which supports the spider, 40. When the motor 55 is actuated, the planetary or epieyclic gearing in the chamber 57 rotates the driving sleeve 42.

The latter in turn swings the spider 40 and the axle 39 so as to cause the mullers 38 to move in a circular path and effect the desired mulling or mixing of the sand on the subjacent portion of the belt 8. The axle 39 is provided with a pair of collars 69. The latter are movable vertically in elongated slots 70 in the spider so that the axle 39 is movable vertically and permits the mullers to raise and lowerin response to variations in the thickness of the layer of sand on the conveyor. .The collars 69 are supported by a pair of adjusting screws 71 so that the shaft 39 is sustained in .a position wherein the mullers 38' are out of contact with the conveyor. The screws 71 extend through the lower part of the spider 40 and are adapted to be locked in place against rotation by lock nuts 72; By adjusting thescrews 71, the mullers38 may be raised or lowered into the desired position with respect to the endless belt on which the sand is supported. The mullers are mounted in bronze bushings 73 which surround the outer ends of the shaft 39 and are positioned between the collars 69 and a pair of retaining devices 74. The latter .are connected to the ends of the shaft 39 and-are disposed in cup-shaped houslugs 75 so that sand is excluded therefrom. Themullers 38 are provided with'tires 38*. These tires are formed of hard rubber and are cemented or otherwise secured to the periphepries of the mullers. A characteristic and an advantage of" utilizing rubber tires on the mullers is that the sand which is yieldingly supported by the belt isyieldingly engaged by the mullers and as a result is mulled quickly and 'without damage of being pulverized to too great an extent. In practice it been found that tires which are substantially equal indensity to solid screws 91.

pressure, and is mulled uniformly and evenly.

By precluding the possibility of excessive crushing or pulverizing the mulled sand when rammed into a flask to form a mold has the necessary permeability to permit of the escape of gases emanating from the molten metal during the pouring operation. In 'view of the fact that the sand is fed by the belt during operation of the mulling units and the coacting mulling surfaces are formed of rubber, the sand is efliciently and quicklymulled to the desired extent.

To turn the sand over and direct it into the path of the mullers during operation of the units 10, rakes 40 are provided. These rakes are adjustably mounted on horizontally extending arms 40" which project outwardly from the spiders 40 and are arranged at right angles to the axles 39. The reservoir 9 operates to store the sand that described, to supply the sand in regulated quantity to the receiving end of the belt 8. It is pref erably-elongated as indicated in Figures 1, 2 and 3, and is supported upon a, framework 76 which is located in front of the receiving end of the conveyor supporting frame. The framework 76 comprises a pair of channel iron sills 77 which are arranged in parallel relation and are supported by means of standards 78. The latter are mounted on and project upwardly from a base 79 which rests upon" the floor of the foundry. The sides of the reservoir are flxed to the sills 77 by means of angle iron bars 80 which are bolted or otherwise secured to the top flanges of the sills. The top of the reservoir is open sothat it can be fllled from an overhead sand delivery system or in any other suitable manner. The bottom of the reservoiris formed by an endless conveyor 81 which is adapted to feed the sand forwardly through a discharge opening 82 in the front wall of the reservoir. This conveyor consists of an endless series of slats 83. The latter are shaped so tlmt they overlay one another and are connected to apair of endless chains 84 by-means of pivot lugs 85. The rear ends of the chains extend-around a pair of sprocket wheels 86 which are mounted on a transversely extending shaft 87., The ends of this shaft extend through elonated slots 88 in the rear ends of the sills 77 and are journalled in bearing blocks 89 which are slidably mounted in guideways 90. The latter are secured to the sills 77 and are connected to the bearing blocks 89 by means of When it is desired to tighten the conveyor 81, the screws 91 are adjusted so as to shift the bearing blocks 89 and the shaft 87. The front ends of the chains 84 extend around a pair of .driving sprockets 92 which are mounted .on a transversely extending shaft 93. The latter is located beneath the discharge opening 82 and is arranged so that the ends thereof project through the front ends of the channel iron sills 77., The-conveyor 81 is operated to feed the sand step by stepthrough the'discharge is to be mulled and operates; as hereinafter which is mounted on and operated by the eccentric; and a ratchet wheel 97 which is fixed en by the mechanism heretofore described, the

sand is fed through 'the discharge opening 82. From said discharge opening 82, the sand passes onto a chute 98. The latter is connected to the front ends of the sills '77 and is adapted to direct the sand onto the receiving end of the endless belt 8.

The discharge of sand through the opening 82 is controlled by means of a gate 99 which is vertically movable and is in the nature of a valve whereby the height of the. discharge opening may be varied to regulate the quantity of sand that is discharged from the reservoir. The gate is supported by a pair of arms 100 which project rearwardly and are pivoted to the sides of the reservoir so that the gate can swing upwardly or downwardly. The arms are preferably arranged so that the gate will be shifted upwardly when engaged by scrap in the sand in order to permit such scrap to pass thereunderv and move out of a position wherein it would tend to obstruct the discharge opening and interfere with the regulated delivery of the sand. The raising and lowering of the gate is effected by means of mechanism which comprises a transversely extending shaft 101, a drum 102 on the shaft and a cable 103. The latter is wound around the drum and is connected at its distal end to the gate 99. The shaft 101 is adapted to be turned for drum rotating purposes by means of a hand wheel 104. When the hand wheel is turned. in one direction, the drum 102 is rotated so as to cause the cable to wind thereon and raise the gate 99. When the hand wheel 104 is turned in the opposite direction, a lowering of the gate is effected. The gate 99 and the conveyor 81 exemplify means for supplying sand in regulated quantity to the receiving end of the endless belt 8. By providing sand supply means of the character herein described, the sand is caused to be distributed evenly over the belt 8 and is in the nature of a layer which is substantially of uniform thickness throughout,

Assuming that the various motors are running, the operation of the mulling apparatus is as follows:

The endless conveyor 81 is riioved step by step by means of the pawl and ratchet and causes the sand in the reservoir 9 to be fed onto the chute 98. The gate 99 controls the discharge of the sand through the opening 82 so that the feeding of the sand is uniform and the sand is caused to be delivered'onto the belt 8 in the form of a layer of uniform thickness. Said belt operates to convey the sand from the chute 98 towards the discharge end of the supporting frame. As

the sand is moved on the belt 8 under the mullers 38, the desired mulling takes place. By virtue of the fact that the tires and the belt engage the sand yieldingly and frictionally the mulling is done expeditiously and without likelihood of excessive pulverizing or crushing. After the sand has been subjected to the action of the mulling units it is discharged from the belt 8 and isin readiness for use in connection with molding. The mullers 3B are preferably supported so that they are positioned a slight distance above the endless belt 8. By supporting the mullers in this manner, wear of the tires and the belt discharge opening. If it is desired to deliver the sand to the belt 8 in comparatively small quantities, the gate 99 is lowered so as to decrease the size of the discharge opening 82. In the event that the gate encounters scrap in the sand it'is automatically forced upwardly so as to permit such scrap to pass thereunder.

The mulling apparatus herein disclosed is exceedingly efiicient in operation in view of the fact that the endless belt permits of a continuous operation and serves to move the sand progressively into and out of the path of travel of the mullers. Since the belt is formed of rubber it presents a smooth and even supporting surface for'the sand and is sufliciently yielding to prevent the possibility of the sand being crushed to too great an extent.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without deparing from the spirit and scope of the invention. Q

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a mulling apparatus of the character described, the combination ofsupporting means,

an endless belt for supporting the material to be mulled, carried bythe supporting means and formed of elastic material so as to support the material yieldingly, a muller positioned above the belt and adapted to operate on the material, and means for driving said belt so as to feed the material progressively under the muller for mulling purposes.

2. In a mulling apparatus of the character described, the combination of a frame, an endless rubber belt carried by said frame and operative to support the material to be mulled, a power driven mulling unit comprising a muller positioned above the belt and movable bodily in a circular path over the material for mulling purposes, and means for driving the belt so as to feed the material progressively into the path of travel of the material.

3. In a mulling apparatus of the character described, the combination of a frame, an endless rubber belt carried by said frame and adapted to support the material to be mulled, a powerdriven mulling unit comprising a muller wheel positioned above the belt and movable bodily in a circular path over the material, said muller wheel being provided with a rubber tire and adapted, during operation of the unit, to engage frame-sides comprising a mullet wheel positioned moving the member reetilinearly so as to feed the material progressively into the path of travel of the wheel and efiect, during moving of the wheel, an efificient and ready mulling of the material by tthe combined movements of the mullet and the wheel.

GEO. FURMA N. 

